SEO has a lot of moving parts. Successfully getting your content to rank highly and stand out from the vast ocean of blog posts, articles, website content, videos, infographics, and other types of informative and persuasive marketing pieces being produced requires making sure no component is missing and everything is working together.
Optimizing all of the factors that can impact search ranking can be approached in different ways. One is to assemble a collection of best of breed tools; previous posts here have covered tools for competitive intelligence, content planning, keyword research, rank tracking, and special-purpose SEO tools for functions like technical SEO, link research, and video SEO.
Another approach is to implement an all-in-one SEO tools suite, which covers most if not all the bases in a single package. Which approach is best for your organization depends on a variety of factors. Generally, best-of-breed tools offer greater functional depth, while all-in-one suites simplify management and integration.